Answer:√3/2
From trignometric formula
Sin (90 + x) = cos x
So sin 120° can be written as
Sin (90°+ 30°) = cos 30°
Sin Values
sin 0° = √(0/4) = 0
sin 30° = √(1/4) = ½
sin 45° = √(2/4) = 1/√2
sin 60° = √3/4 = √3/2
cos 90° = √(4/4) = 1
Cos Values
cos 0° = √(4/4) = 1
cos 30° = √(3/4) = √3/2
cos 45° = √(2/4) = 1/√2
cos 60° = √(1/4) = 1/2
cos 90° = √(0/4) = 0
From the above list of cos value
Cos 30° = √3/2
So
Sin (120°) = Sin (90°+ 30°) = cos 30° = √3/2
